Liquid crystal display devices are thin, light, and consume little power, and are therefore widely used as display equipment for televisions, personal computers, PDAs, and the like. These days, in particular, larger liquid crystal display devices have been rapidly introduced, as typically exemplified by liquid crystal display devices for TVs. For enlarging of the size, multi-domain vertical alignment (MVA) mode liquid crystal display devices are favorably developed because even those with large areas, which can be produced at a high yield even if they have large areas, and also which have a wide viewing angle, are favorably developed. In the case of multidomain vertical alignment mode, liquid crystal molecules are aligned perpendicularly to a substrate surface when no voltage is applied in a liquid crystal layer. Therefore, a higher contrast ratio can be achieved as compared to conventional twisted nematic (TN) mode.
However, since ribs (protrusions) are formed in MVA mode, problematically the aperture ratio decreases, resulting in reduction in the white luminance. This problem is solved when the distances among ribs are sufficiently large, while the number of the ribs which are alignment-controlling structures is reduced. As a result, a longer time is required for stability of the alignment of liquid crystals after application of a predetermined voltage, problematically increasing the response time. In order to solve the above problems and to enable high luminance and high-speed response, a technology for providing pretilt angles by use of polymers (hereinafter, also referred to as PSA (polymer sustained alignment) layers) is proposed (see, for example, Patent Literatures 1 to 4). In PSA technology, a liquid crystal composition including liquid crystals and polymerizable components such as monomers and oligomers (hereinafter, abbreviated as monomers, etc.) is enclosed between substrates. Then, a voltage is applied between the substrates so that the monomers, etc. are polymerized, with the liquid crystal molecules tilting, to form a polymer. As a result, after removal of the applied voltage, the liquid crystals have a predetermined pretilt angle. Thus, the alignment direction of the liquid crystals can be set. Polymerization of the monomers, etc. is initiated by heat or light (ultraviolet rays) irradiation. The PSA technology needs no ribs, and thus the aperture ratio is improved. At the same time, a pretilt angle of less than 90 degree is provided on the entire display area, thereby enabling high-speed response.